1. Field of the Invention
The invention relates to a connector which is composed of a receptacle connector and a plug connector to be coupled to each other for electric connection, and a portable terminal which includes such a connector.
2. Description of the Related Art
Connectors having a receptacle connector and a plug connector, the plug connector being plugged into a plug-in slot of the receptacle connector for electric connection, are used in portable terminals and other devices. Due to miniaturization of such terminals and devices, demands for reduced height of the connector and smaller on-board areas, i.e., miniaturization of the connectors, have been growing.
However, due to such miniaturization, there are problems with such connectors fitting poorly since it is more difficult to visually check a connector fit and the manual positioning, and due to the reduced height of the connectors, slopes for guiding one of the connectors also are required to be made smaller. In view of such problems, there has been proposed a connector in which such guidance slopes are made as large as possible in order to improve the fitting thereof (Japanese Patent Laid-Open Publication No. 2001-273949).
Due to proliferation and intensified sales competition for portable terminals, demands have been growing for higher volume of production and lower cost. One of the measures being taken is the rapid automation of assembly processes. When automating the connector assembly, it is particularly difficult to automate the process of fitting a plug connector to a receptacle connector (mechanically automated fitting of connectors will be hereinafter referred to as automatic fitting) because of positioning accuracy before fitting. More specifically, in a typical assembly process of a connector, a plug connector which is mounted on an FPC board or the like is temporarily placed on a receptacle connector which is mounted on another board. Subsequently, the plug connector is press-fitted from the underside in an assembling machine. If this assembly is automated, it is difficult to improve the positioning accuracy from the temporary placement to the press fit. For this reason, there has been a high demand for connectors that can be fitted in a correct position even if the plug connector and the receptacle connector (yet to be fitted) are largely deviated from the fitting position thereof.
However, in the above-described electrical connectors, it has been difficult to achieve a reduced height while allowing for large fitting deviations which can occur due to manual fitting under poor visibility or can occur during an automatic fitting process. It has been particularly difficult to deal with fitting deviations if the clearance between the boards to be fitted is no greater than 2 mm. Moreover, the connectors often have a generally rectangular shape (in plan view), and the plug-in slot for the plug connector to be plugged in is formed along the longitudinal or lateral direction of the connector. As a result, rotational deviation can occur easily, which leads to a drop in efficiency of the fitting operation. When the electric connectors are force-fitted automatically without absorbing such fitting deviations, contacts may suffer buckling and other damage, and can cause the connector bodies to break. Even if the fitting deviations were to be absorbed, the connectors are hard to align properly and thus tend to be fitted obliquely, which can increase and vary the fitting force, and moreover, results in difficultly in confirming a correct fitting thereof, normally felt by the connector clicking into place.